1. Field of the Invention
The present invention pertains to the use of recycled lubricating oil and more particularly to the use of recycled lubricating oil as a fuel and a source of heat for processes requiring thermal generation.
2. Related Art
Recycled Fuel Oil is a by-product of used motor oil obtained primarily from the crankcases of internal combustion engines. It is disposed of when it is time to change the oil in any specific internal combustion engine. The used motor oil then becomes a waste stream for which proper disposal methods must be followed. The disposal methods must conform to those promulgated according to EPA regulations.
In using recycled oil as a fuel, there are several possible approaches. One approach may be to design the burner around the inconsistent quality of oil while another may be to try to improve the quality of the recycled oil. In the first approach, the inconsistency of recycled oil and its varying quality are recognized in the type of burner designed for its use. Such a burner is described below.
U.S. Pat. No. 5,405,261 titled “Waste Oil Fired Heater with Improved Two-Stage Combustion Chamber” issued to Charles R. Scraggs et al. relates to a burner that was designed for recycled oil with its varying viscosity. A two-stage combustion chamber for burning waste hydrocarbons such as crank case oil, spent motor oil, transmission fluid, lubrication dopes and heavy bodied gear lubes. The combustion chamber is formed from a plurality of spaced apart, stacked annular rings that form a flame containment housing having superheated surfaces. The flame containment housing contains the flame of an atomizing oil burner suitable for burning the variable viscosity waste hydrocarbons. The annular rings include outer walls and inwardly extending flanges that intercept unburned fuel droplets and combustion byproducts, vaporizing the droplets and stimulating secondary combustion. The annular rings are removable and replaceable and are supported in spaced apart relation by spacers on a plurality of support rods. Combustion byproducts and unburned fuel droplets are deflected by the flanges of the annular rings and vaporized or subjected to secondary combustion, thereby minimizing condensation on the relatively cool surfaces of a heat exchanger positioned close to the combustion chamber. The combustion chamber is thus useful in a heat transfer apparatus for heating water or air with waste hydrocarbons.
The second approach to using recycled oil as a fuel, improving the quality of the oil, is to precondition the recycled oil to approximate the quality of number two fuel oil. This approach attempts to remove contaminants either through a mechanical means or a chemical means.
U.S. Pat. No. 5,855,768 titled “Process for Removing Contaminants from Thermally Cracked Waste Oils”, issued to Maria Stanciulescu et al. relates to a chemical method of removing contaminants from recycled oil. The process is one for removing contaminants from thermally cracked waste oil, such as, used motor oil. The cracked waste oil is contacted with a solvent comprising methanol. The thermally cracked waste oil is then separated from the solvent whereby a substantial portion of the contaminants are removed into the solvent. Thereafter, the solvent is separated from the contaminants and recycled.
U.S. Pat. No. 5,885,444 titled “Process for Converting Waste Motor Oil to Diesel Fuel”, issued to Robert W. Wansbrough et al. relates to a method for reprocessing waste motor oil in a cracking tower similar to those used to initially process oil when it is first brought up from the ground to produce a diesel fuel. The thermal cracking process uses low temperature cracking temperatures from 625 degrees F. to 726 degrees F. with ambient pressure to generate a column distilled fraction of diesel fuel mixed with light ends, the light ends being fleshed off to produce a high quality #2 diesel fuel. The process further provides for removal from the cracking vessel an additional product stream which, when filtered, is suitable for use as a #3 fuel oil and that can be further blended with a bunker oil to yield a #5 fuel product.
U.S. Pat. No. 5,510,023 titled Oil Recycling Apparatus with a Recirculating Filtration Line”, issued to John I. Taylor relates to a mechanical device for conditioning recycled oil. The device has a container with an access lid for inserting the oil to be processed. A heater is provided to insure that the oil will be of a temperature that it will be properly processed. A filter system is included which is mounted on top of the container, A pump moves the oil from the bottom of the container to the bottom of the filter system. Pressure then forces the oil through the filter system to a pipe which moves the oil back to the container for another cycle. Oil is continuously recycled from and back to the container for several hours until the oil is clear. It is then ready for removal and reuse.
In one situation, the use of recycled oil as a fuel requires a specially designed burner to handle the inconsistent quality and viscosity of the recycled oil. In another situation, the reconditioning process of recycled oil to make it acceptable is slow and inefficient. The method and apparatus of the present invention responds to both problems.